package khelpcenter (not installed) failed to install/upgrade: trying to overwrite '/usr/share/locale/si/LC_MESSAGES/htmlsearch.mo', which is also in package kde-l10n-si 4:4.10.97-0ubuntu1

This happened to me several times on Ubuntu 15.04, while I was trying to install packages "Tellico' and 'Eqonomize!. I tried AskUbuntu and the solutions given do not work. For instance I was advised to backup before installing packages with the command Y-ppa-manager and when I use it the terminal says there is no such command.
Then I formatted the computer and installed Ubuntu 15.10 and once again the same problem crops up when I was trying to install 'Tellico'.

ProblemType: Package
DistroRelease: Ubuntu 15.10
Package: khelpcenter (not installed)
ProcVersionSignature: Ubuntu 4.2.0-23.28-generic 4.2.6
Uname: Linux 4.2.0-23-generic i686
ApportVersion: 2.19.1-0ubuntu5
Architecture: i386
Date: Tue Jan 5 21:46:39 2016
DuplicateSignature: package:khelpcenter:(not installed):trying to overwrite '/usr/share/locale/si/LC_MESSAGES/htmlsearch.mo', which is also in package kde-l10n-si 4:4.10.97-0ubuntu1
ErrorMessage: trying to overwrite '/usr/share/locale/si/LC_MESSAGES/htmlsearch.mo', which is also in package kde-l10n-si 4:4.10.97-0ubuntu1
InstallationDate: Installed on 2015-12-14 (22 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release i386 (20150422)
RelatedPackageVersions:
 dpkg 1.18.2ubuntu5.1
 apt 1.0.10.2ubuntu1
SourcePackage: khelpcenter
Title: package khelpcenter (not installed) failed to install/upgrade: trying to overwrite '/usr/share/locale/si/LC_MESSAGES/htmlsearch.mo', which is also in package kde-l10n-si 4:4.10.97-0ubuntu1
UpgradeStatus: Upgraded to wily on 2016-01-01 (4 days ago)